The present invention relates to safety switches.
Safety switches are often used to control the supply of electricity to electrically powered machinery. Typically, a safety switch is located on a doorpost of an enclosure inside which is located kinetic machinery. On the door to the enclosure is located an actuator which is engageable with the safety switch. When the door to the enclosure is opened, the actuator is not in engagement with the safety switch. As a consequence of this, electrical contacts within the safety switch are kept apart, which means that electricity may not be supplied to the machinery within the enclosure. Thus, a user may enter and move around the enclosure with a reduced risk of injury, since the machinery is not operating. If the door to the enclosure is closed, the actuator is brought into engagement with the safety switch. The contacts in the safety switch are then brought into contact with each other such that electricity may be supplied to the machinery within the enclosure. This sort of arrangement, which is often referred to as a safety interlock, is used in a wide variety of applications. However, depending upon the internal workings of the safety switch, the safety switch may sometimes fail to danger. For example, if the safety switch becomes damaged in one of a number of ways, the contacts within the switch may close. This allows electricity to be supplied to machinery within the enclosure regardless of whether the actuator is engaged or disengaged with the safety switch.
It is therefore an aspect of the present invention to obviate or mitigate a disadvantage of the prior art, whether mentioned herein or elsewhere.